CDI Calculator: How to Calculate Fixed Income Returns
Learn what CDI is, current rates, and how to calculate returns on Brazilian fixed income investments. Free calculator included.
The CDI (Certificado de Depósito Interbancário - Interbank Deposit Certificate) is the main benchmark for fixed income investments in Brazil. It represents the average rate of loans between banks and serves as a reference for more than 90% of fixed income products available in the market.
If you want to understand how the CDI affects your investments and calculate the real returns on your applications, this guide provides all the practical information you need.
What is CDI
Definition and importance
The CDI is a credit instrument that banks issue to lend money to each other in the very short term. These operations last only one day and serve for financial institutions to adjust their daily cash flows.
The CDI rate functions as the “thermometer” of the Brazilian economy. When the Central Bank raises the Selic rate, the CDI rises along with it. The CDI always stays about 0.1 to 0.15 percentage points below the Selic.
How CDI is formed
The CDI is calculated by CETIP (now B3) based on actual operations between banks:
- Schedule: Calculated daily until 7 PM
- Base: Weighted average of the day’s operations
- Release: Available at the end of each business day
- Accumulation: Annual rate formed by daily compounding
Current CDI rate
Daily and monthly variation
The CDI rate today is around 11.25% per year (January 2024), following the Selic rate of 11.75%. This rate changes daily, but variations are minimal — usually from 0.01% to 0.03%.
The CDI accumulates daily compound interest. This means that each day, interest is applied to the previous value already adjusted.
Example: R$ 10,000 invested at 100% of CDI (11.25% p.a.) yields approximately R$ 1,125 in 12 months, considering compound interest.
Recent history
See how the CDI has evolved in recent years:
| Period | Average CDI | Economic Context |
|---|---|---|
| 2021 | 4.39% | Low interest rates, pandemic |
| 2022 | 9.15% | Beginning of Selic rise |
| 2023 | 12.45% | Peak of rising cycle |
| 2024 | 11.25% | Stabilization |
How to calculate CDI returns
Calculation formula
CDI calculation follows the compound interest formula:
Final Value = Initial Value × (1 + daily CDI)^days
For quick calculations, you can use our CDI calculator which does all calculations automatically, including income tax discounts.
CDI vs percentage of CDI
Most investments offer a percentage of CDI, not 100%:
- Pre-fixed CDB: Usually between 90% to 115% of CDI
- LCI/LCA: Between 85% to 95% of CDI (tax-exempt)
- DI Funds: About 95% of CDI after fees
Practical example: A CDB paying 105% of CDI with current rate of 11.25% will yield 11.81% per year gross before Income Tax.
Income Tax impact
Income tax on fixed income investments follows the regressive table:
- Up to 180 days: 22.5%
- 181 to 360 days: 20%
- 361 to 720 days: 17.5%
- Over 720 days: 15%
CDI-linked investments
CDB, LCI and LCA
The main fixed income products follow the CDI:
CDB (Certificado de Depósito Bancário - Bank Deposit Certificate):
- FGC guarantee up to R$ 250,000
- Income tax taxation
- CDI percentage varies by bank and term
LCI/LCA (Letras de Crédito - Credit Letters):
- Income Tax exempt
- Focused on real estate credit (LCI) or agribusiness (LCA)
- Lower CDI percentage than CDB
DI Funds
DI funds invest in CDI-linked securities and offer daily liquidity. Main characteristics:
- D+1 redemption
- Management fee (0.3% to 2% per year)
- Come-cotas: Income tax charged semi-annually
- Net return usually between 90% to 95% of CDI
CDI vs other investments
Comparison with savings account
Savings accounts yield 0.5% per month + TR when Selic is above 8.5%. With current CDI:
| Investment | Annual Return | Taxation | Liquidity |
|---|---|---|---|
| Savings | ~6.17% | Exempt | Immediate |
| 100% CDI | 11.25% | Regressive income tax | Varies |
| 90% CDI LCI | 10.13% | Exempt | 90+ days |
CDI beats savings accounts even with income tax discount, especially for investments over 2 years.
Comparison with Treasury Direct
For conservative investments, compare CDI with government bonds:
- Treasury Selic: Follows 100% of Selic, daily liquidity
- 100% CDI CDB: Similar profitability, but limited by FGC
- Treasury IPCA+: Protects against inflation, ideal for long terms
CDI investment simulator
To calculate exactly how much your CDI-linked investments will yield, use our specialized calculator.
How to use the simulator
The tool allows you to simulate:
- Initial value and monthly contributions
- CDI percentage offered by the product
- Investment term
- Automatic income tax discount by time bracket
Tip: Always compare net returns (after income tax) between different products. LCIs and LCAs with 85% of CDI may outperform CDBs at 105% of CDI due to tax exemption.
Practical strategies
To optimize CDI investments:
- Short term (up to 1 year): Prefer DI funds for liquidity
- Medium term (1-2 years): CDBs with high CDI percentage
- Long term (2+ years): LCI/LCA for income tax exemption
Frequently Asked Questions
What is today’s CDI rate?
The current CDI rate is approximately 11.25% per year, varying daily according to interbank operations. This rate closely follows the Selic, staying about 0.1 to 0.15 points below.
How to calculate CDI returns?
Use the formula: Final Value = Initial Value × (1 + daily CDI)^days. For convenience, use our CDI calculator which automatically includes Income Tax discount.
Is CDI better than savings?
Yes, CDI beats savings even with income tax discount. With CDI at 11.25% and savings at ~6.17%, CDI investments yield almost double, especially for terms over 2 years when income tax drops to 15%.
What’s the difference between 100% CDI and 110% CDI?
An investment at 110% of CDI yields 10% more than pure CDI. With CDI at 11.25%, you would receive 12.38% per year gross. Always compare net returns (after income tax) to make the best decision.
LCI or CDI-linked CDB?
It depends on the percentage offered. LCIs are income tax exempt but pay lower CDI percentage (85-95%). CDBs pay more (100-115%) but have income tax. For long terms, LCIs with 90%+ of CDI usually outperform CDBs.
How to track daily CDI variation?
CDI is published daily by B3 until 7 PM. You can track it on B3’s website, investment apps, or specialized sites. Daily variations are small, but monthly accumulation is significant.
Do DI funds yield 100% of CDI?
No. DI funds discount management fees (0.3% to 2% per year) and have other costs. Net return stays between 90% to 95% of CDI, but they offer daily liquidity that other products don’t have.